Cable maintenance apparatus



pril 18, 1933.

T. C. HENNEBERGER CABLE MAINTENANCE APPARATUS Filed Jan. 2, 1930 /VZarnb`11ressure f' Guayas Quad m awk am@ Paff- V INVENTOR Z'Clelm eblyef "f Ls1 C ATTORNEY Patented Apr. 18 1933 @UNITED s'rn'rrzsl THOMAS G.HENNEBEBGER, OF BLOOFIELD, NEW JERSEY, ASSIGNOB TO AMERICAN TIEILEPHONEAND TELEGRAIH CDMIANY, A CORPORATION OF NEW YORK VGAIBIE MAINTENANCEAPPARATUS Application filed 'January 2, 1930. Serial No. 418,144.

This invention relates to apparatus for use in connection with themaintenance of cables, and more particularly to apparatus for use withcables which are held continuously under gas pressure. p

. ylfhe purposes of maintaining cables under pressure are to prevent theentrance of moisture into the cable and to permit the locating of sheathopenings before the occurrence of insulation trouble. To provide meanstor detecting loss of pressure,the cable may be isolated into sectionsof convenient length by gas-tight plugs, and pressure gauges, associatedwith an electric alarm circuit, may be installed atv one ormore pointsalong each isolated section. The two pairs of a spare quad inthe cableare ordinarily used to form the wires of the alarm circuit and the wiresot a talking circuit for the use o field men. The pressure gauges areadapted to be connec-ted in parallel across the alarm pair. At each etthe'points where the alarm pair is brought out of the cable forconnection to a gauge, terminal facilities are usually provided throughwhich the desired connections be made for the talking-pair, the alarmpair and the pressure gauge.

@ne object of the present invention is the provision of terminalfacilities suited to the above-stated use. Another' object of theinvention is the provision of a suitable combi; nation ci: cableterminal vand low pressure alarm contactor for use with a cablemaintained under pressure. A further object of the invention is theprovision of terminal apparatus adapted not only for suitablecombinationwith a low pressure alarm contactor but also for use with the contactorremoved, as in the case in which it is desired to bring out :from thecableonly the talking pair.

ln general, the invention takes the form of an arrangement ofa gas-tightchamber adapted ier connection with a cable sleeve or the like, bindingposts and suitable means for elif-acting the desired connection betweenthe chamber and the binding posts and a low pressure alarm contactor.The invention will be clearly understoo when the following detaileddescription of the most partv in section on the line 3 3 of Fig. 2; v

llig. 4 is a sectional view of the apparatus intermediate to theterminal and the contactor, taken on the line 4 4 of Fig. 3;

Fig. 5 is a similar view taken on line 5 5 of Fig. 3;

Fig. 6 is a sectional view taken approximately on the line 6 6 of `Fig.4 or on the line 6 6 of Fig. 5; and

Fig. 7 is a diagram indicating the circuit connections made through theterminal.

- Likenumerals of reference in the several iigures of the drawingdesignate correspondmg parts.

With reference, vrst, to -`Fig. 1 of the drawing, two gauges areindicated connected in parallel across the alarm pair, which termi natesin suitable apparatus, such as the relay and bell indicated, at arepeater station, for instance. At each of the gauge points, the diagramindicates that the talking pair and the alarm pair are brought out forconnection or looping through a terminal.

With reference, now, to the other figures of the drawing, the terminal 8consists essentially of a. gas-tight metal chamber 9 with a bolted faceplate 10 through which extend insulated binding posts 11, 12, 13, 14,15, 16, i17, 18, 19 and 20. A gasketed cover 21, which should bewater-tight but is not necessarily gas-tight, may be added to protectthe binding posts, which projectinto the watertight chamber 22. Thechamber 9 should be made gas-tight by the use of a gasket v23 for thefaceplate 10 and the use of gaskets such as 24 for the binding posts.The cover 21 may be securely closed by the use of wing nuts such as 25and 26.

, but differs from the ordinary arrangements based on this principle inthat the inside of the Bourdon tube 29 is at atmospheric-pressure, andthis tube, when curled by suiicient pressure in the device 28, holdscontact springs 30 and 31 open. When the pressure introduced through thehousing decreases, the tube 29 tends to straighten and closes theContact of springs 3() and 31. It will be understood that any suitablelow pressure alarm contactor which operates in substantially thismanner, may be employed in place of that specifically shown in F 2. Theterminal is provided, at 151e oppositev end of the chamber 9 to that towhich is attached the sleeve 27, with a reducing nipple 32, and theconnection is made to the con-I tactor 28 vthrough the piperunion 33 andthe reducing nipple 34. Jack apparatus is mounted in the insulatingmember 35 of the reducing nipple 32,l and plug apparatus isl mounted inthe insulating member 36 of reducing nipple 34. One plug takes the formof a central metal pin 37, and the other plug takes the form of a metaltubing 38 molded in the -insulating material concentrically with the pin37. The jack springs 41 are mounted in the insulating member 35, andsuitable receptacles are provided vfor the engagement of these springswith the in 37 and the tub- 1ng 38. The plug and ack assemblies are, ofcourse, tightly secured in their respective reducing nipples 34 and 32,and holes 39 and 40 and 39 and 40 (see Figs. 4 and 5 and indication of40 and 40'/ in Fig. 3) are provlded to permit the gas to pass from thechamber 9 of the terminal into the contactor 28.

It will be understood thatin Fig. 3 the right portions ofthe members 35and 36 are b shown without full regard for the sectional vlew on line ofFig. 2 in order to indicate the positions of the openings 40 and 40. Itwill be understood further that openings 39and 39', not shown in thisfigure, correspond to the openings 40 and 40 respectively. The locationsof the openings 39, 40, 39' and 40 are accurately indicated in Figs. 4and 5.

As has .been stated above, the wires from the cable are carried' throughthe sleeve 27 to the terminalchamber 9, and' the gas. from the cable. isadmitted to the chamber 9. If the terminal but not the contactor is tobe used, the reducing nipple 32 can be calpped, and the terminal 8 willfunction suitab y for a poit at which it is desired to bring out l onlya talking pair. The terminal, of course,

provides facilities for looping the alarm and talking pairs, If, on theother hand, the low pressure alarm contactor is to be combined with theterminal 8, the connecting arrangement shown is most advantageous. Thecon-l In Fig. 7, the wires v42form the section of' the alarm pairpassing into the terminal, and

wires 43 form the section of the alarm pair passing out of the terminal-These pairs are connected to binding posts 13and 14, and 15 and r16,respectively. The wires 44 form the section lof the talking pair passinginto the cable to binding posts 17 and 18, while wires 45 form thesection of the talking pair" 'passing out 'of the terminal from bindingposts 19 and 20. The wires. 46 connect binding posts 11 and 12 to thethe reducing nipple 32.

As indicated above, when the pressureinthe cable is normal, the tube 29of the contactor operates to hold the springs 30 and 31 apart,

jack-springs 41 in I and the alarm circuit (Fig. 1) is open. If,

however, the cable pressure falls below the normal value, or below apredeterminedvalue,r the decrease ofpressure operates to cause thestraightening tendency of the-tube 29, and the making of contact betweensprings 30 and 31, and the alarm circuit is closed to operate the alarmbell or other device at the repeater station.

What is claimed is: 1. A `cable terminal device, comprising a gas-tightchamber and a lurality of binding posts extending throug a. wallthereof, meansassociated with one end of said chamer for connecting thesame to a cable sleeve or the like, a low pressure alarm contactor ofthe Bourdon tube type but having the inside f of the pressure responsiveelement at atmospheric pressure, and a connector between the l other endof said chamber and said contactor including meansv for effectingelectrical connections between certain of said binding posts and thecontacts of the contactor, said-connector being perforated to admit gasfrom said chamber to the interior of the contactor. l 2. Acable terminaldevice, comprising a gas-tight chamber and a. plurality of bindln postsextending through a wall thereo las means associated with one end ofsaid chainber for connecting the same to a cable sleeve or the like, alow pressure alarm contactor of the Bourdon tube type but having theinside of the pressure-responsive element at atmospheric pressure, and aconcentric connector between the other end of said chamber and saidcontacter including means for 'i'ect ing electrical connections betweencertain of said binding posts and the contacts of the contactor, saidconnector being perforated to admit gas from said chamber to theinterior of the contactor.

3. A cable terminal device, comprising a gas-tight chamber and aplurality of binding posts, extending through a wall thereof, meansassociated with one end of said cham'- ber for connecting the same to acable sleeve or the like, a low pressure alarm contactor of ther Bourdontube type but having the inside of the pressure-responsive element atatmospheric pressure, and a connector for y connecting the other end ofsaid chamber and s aid contactor to admit gas to the interior of thecontactor, said ,connector including means to effect electricalconnections between certain of said binding posts and the contacts ofthe contactor, said electrical connections being independent of rotationof said contactor with respect to the gas-tight chamber. Intestimony'whereof, I have signed my name to this specification this 31stday of .December 1929.

35 THOMAS c. HENNEBERGER.

